THE EFFECTS OF L-CARNITINE SUPPLEMENTATION ON BODY WEIGHT, BODY FAT PERCENTAGE AND FAT METABOLISM

Abstract

INTRODUCTION: L-carnitine is a nutritional ergogenic aid. Long chain fatty acids are a major source of energy at rest and during exercise for the body. L-carnitine is an enzyme that transports these fatty acids to the mitochondria for beta oxidation. It has been theorized that by increasing L-carnitine availability, fat oxidation will be increased within the body and glycogen can be spared, thus, increasing aerobic endurance capacity. Previous studies have shown mixed results. PURPOSE: The purpose of this study was to determine whether 10 days of L-carnitine supplementation in a recreationally active college-aged sample would result in increased fat metabolism. METHODS: Five recreationally active young adults volunteered to be a part of this study. Two females (W: age 20.5 ± 3.5 years) and three males (M; age 21.7 ± 3.2 years). Each subject had their body weight and body fat percentage calculated through a bioelectrical impedance analysis (BIA) scale, and then performed a 20 minute submaximal exercise test at 65% of age-predicted maximal heart rate. During each exercise test, heart rate (HR), blood pressure (BP) and rate of perceived exertion (RPE) was recorded along with, volume of oxygen consumed (VO2), volume of carbon dioxide expired (VCO2) and the respiratory quotient (RQ). Subjects were given 500 mg of L-carnitine to take daily and a log to record exercise activity within the 10 day trial. Subjects came in 10 days later and body weight and body fat percentage was recorded again using a BIA scale, and they performed another 20 minute submaximal exercise test, where HR, BP, RPE, VO2, VCO2 and RQ were recorded. RESULTS: No variable reach a significant difference. Pre- and Post-supplementation RQ valve at the midpoint for the exercise test are 1.039 ± .0255 (W), 1.028± .0025 (M) and 0.973 ± .0608 (W), 1.032 ± .0617 (M) respectively. The RQ value throughout entire pre-supplementation exercise test was 1.054 ± .0382 (W) and 1.039 ±.0541 (M), and 0.967 ± .0665 (W), 1.031 ± .0812 (M) for post-supplementation RQ values. Body fat percentage pre-supplementation values include 35% ± 6.36% (W) and 11.7% ±.0 .58% (M). Post-supplementation values include 34% ± 7.07 (W) and 11.3% ± 1.15% (M) . Pre-supplementation VO2 measurements among the subjects include 0.802 ± .250 L/min (W), and 1.441 ± .430 L/min (M), with post-supplementation values including 0.690 ± .080 L/min (W) and 1.492 ± .490 L/min.VCO2 measurements for the subjects pre-supplementation include 0.825 ± .252 L/min (W), and 1.382 ± .409 L/min (M), and post-supplementation values are 0.663 ± .030 L/min (W), and 1.472 ± .458 L/min (M). HR and RPE show no significant difference with supplementation. CONCLUSION: The results of the study concluded that there is no significant difference in fat oxidation, body fat percentage or weight in males or females with 10 days of L-Carnitine supplementation. This might be attributed to the short duration of supplementation period. Also the type, frequency and duration of physical activity the subject participated in also might have had a effect on the effectiveness of the supplementation.